To improve the interfacial stability of spinel phase LiNi05Mn15O4 cathode material in deeply charged state,a nanoscale Al2O3 film was deposited on the surface of single-crystal LiNi0.5Mn1.5O4 by atomic layer deposition in a controlled manner.The modified cathode material exhibits excellent long-cycle performance and corrosion resistance(with capacity retention rate up to 94.7％after 500 cycles at 1C).The surface and interface analysis shows that the nanoscale Al2O3 coating deposited by atomic layer deposition technology can significantly inhibit the corrosion reaction between material and electrolyte,and also constrain the irreversible dissolution and precipitation of transition metal ions.In addition,AlF3 produced by HF surface etching can enhance corrosion resistance of LiNi0.5Mn1.5O4 cathode material,which can thus improve its long-cycle performance and the service performance at high voltage.
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